[cherry-picked] ABCI Vote Extension 2 (#6885)

* add proto, add boilerplates

* add canonical

* fix tests

* add vote signing test

* Update internal/consensus/msgs_test.go

* modify state execution in progress

* add extension signing

* add extension signing

* VoteExtension -> ExtendVote

* modify state execution in progress

* add extension signing

* verify in progress

* modify CommitSig

* fix test

* apply review

* update data structures

* Apply suggestions from code review

* Add comments

* fix test

* VoteExtensionSigned => VoteExtensionToSigned

* Apply suggestions from code review

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>

* *Signed -> *ToSign

* add Vote to RequestExtendVote

* add example VoteExtension

* apply reviews

* fix vote

* Apply suggestions from code review

Co-authored-by: Dev Ojha <ValarDragon@users.noreply.github.com>
Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>

* fix typo, modify proto

* add abcipp_kvstore.go

* add extension test

* fix test

* fix test

* fix test

* fit lint

* uncomment test

* refactor test in progress

* gofmt

* apply review

* fix lint

Co-authored-by: Aleksandr Bezobchuk <alexanderbez@users.noreply.github.com>
Co-authored-by: Dev Ojha <ValarDragon@users.noreply.github.com>

abci/types/application.go

@@ -20,7 +20,9 @@ type Application interface {
 	ProcessProposal(context.Context, *RequestProcessProposal) (*ResponseProcessProposal, error)
 	// Deliver the decided block with its txs to the Application
 	FinalizeBlock(context.Context, *RequestFinalizeBlock) (*ResponseFinalizeBlock, error)
+	// Create application specific vote extension
 	ExtendVote(context.Context, *RequestExtendVote) (*ResponseExtendVote, error)
+	// Verify application's vote extension data
 	VerifyVoteExtension(context.Context, *RequestVerifyVoteExtension) (*ResponseVerifyVoteExtension, error)
 	// Commit the state and return the application Merkle root hash
 	Commit(context.Context, *RequestCommit) (*ResponseCommit, error)

abci/types/types.go

@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 
 	"github.com/cosmos/gogoproto/jsonpb"
+
+	types "github.com/tendermint/tendermint/proto/tendermint/types"
 )
 
 const (
@@ -51,6 +53,16 @@ func (r ResponseProcessProposal) IsStatusUnknown() bool {
 	return r.Status == ResponseProcessProposal_UNKNOWN
 }
 
+// IsOK returns true if Code is OK
+func (r ResponseVerifyVoteExtension) IsOK() bool {
+	return r.Result <= ResponseVerifyVoteExtension_ACCEPT
+}
+
+// IsErr returns true if Code is something other than OK.
+func (r ResponseVerifyVoteExtension) IsErr() bool {
+	return r.Result > ResponseVerifyVoteExtension_ACCEPT
+}
+
 //---------------------------------------------------------------------------
 // override JSON marshaling so we emit defaults (ie. disable omitempty)
 
@@ -156,3 +168,25 @@ func MarshalTxResults(r []*ExecTxResult) ([][]byte, error) {
 	}
 	return s, nil
 }
+
+// -----------------------------------------------
+// construct Result data
+
+func RespondExtendVote(appDataToSign, appDataSelfAuthenticating []byte) ResponseExtendVote {
+	return ResponseExtendVote{
+		VoteExtension: &types.VoteExtension{
+			AppDataToSign:             appDataToSign,
+			AppDataSelfAuthenticating: appDataSelfAuthenticating,
+		},
+	}
+}
+
+func RespondVerifyVoteExtension(ok bool) ResponseVerifyVoteExtension {
+	result := ResponseVerifyVoteExtension_REJECT
+	if ok {
+		result = ResponseVerifyVoteExtension_ACCEPT
+	}
+	return ResponseVerifyVoteExtension{
+		Result: result,
+	}
+}

consensus/common_test.go

@@ -108,6 +108,7 @@ func (vs *validatorStub) signVote(
 		Timestamp:        tmtime.Now(),
 		Type:             voteType,
 		BlockID:          types.BlockID{Hash: hash, PartSetHeader: header},
+		VoteExtension:    types.VoteExtensionFromProto(kvstore.ConstructVoteExtension(pubKey.Address())),
 	}
 	v := vote.ToProto()
 	if err := vs.PrivValidator.SignVote(test.DefaultTestChainID, v); err != nil {
@@ -133,6 +134,10 @@ func signVote(vs *validatorStub, voteType tmproto.SignedMsgType, hash []byte, he
 		panic(fmt.Errorf("failed to sign vote: %v", err))
 	}
 
+	// TODO: remove hardcoded vote extension.
+	// currently set for abci/examples/kvstore/persistent_kvstore.go
+	v.VoteExtension = types.VoteExtensionFromProto(kvstore.ConstructVoteExtension(v.ValidatorAddress))
+
 	vs.lastVote = v
 
 	return v

consensus/state.go

@@ -1971,6 +1971,7 @@ func (cs *State) handleCompleteProposal(blockHeight int64) {
 // Attempt to add the vote. if its a duplicate signature, dupeout the validator
 func (cs *State) tryAddVote(vote *types.Vote, peerID p2p.ID) (bool, error) {
 	added, err := cs.addVote(vote, peerID)
+
 	if err != nil {
 		// If the vote height is off, we'll just ignore it,
 		// But if it's a conflicting sig, add it to the cs.evpool.
@@ -2068,6 +2069,13 @@ func (cs *State) addVote(vote *types.Vote, peerID p2p.ID) (added bool, err error
 		return
 	}
 
+	// Verify VoteExtension if precommit
+	if vote.Type == tmproto.PrecommitType {
+		if err = cs.blockExec.VerifyVoteExtension(vote); err != nil {
+			return false, err
+		}
+	}
+
 	height := cs.Height
 	added, err = cs.Votes.AddVote(vote, peerID)
 	if !added {
@@ -2229,9 +2237,6 @@ func (cs *State) signVote(
 		BlockID:          types.BlockID{Hash: hash, PartSetHeader: header},
 	}
 
-	v := vote.ToProto()
-	err := cs.privValidator.SignVote(cs.state.ChainID, v)
-
 	switch msgType {
 	case tmproto.PrecommitType:
 		// if the signedMessage type is for a precommit, add VoteExtension
@@ -2241,6 +2246,8 @@ func (cs *State) signVote(
 		}
 		vote.VoteExtension = ext
 	}
+	v := vote.ToProto()
+	err := cs.privValidator.SignVote(cs.state.ChainID, v)
 	vote.Signature = v.Signature
 	vote.Timestamp = v.Timestamp
 

state/execution.go

@@ -306,6 +306,23 @@ func (blockExec *BlockExecutor) ExtendVote(vote *types.Vote) (types.VoteExtensio
 	return types.VoteExtensionFromProto(resp.VoteExtension), nil
 }
 
+func (blockExec *BlockExecutor) VerifyVoteExtension(vote *types.Vote) error {
+	req := abci.RequestVerifyVoteExtension{
+		Vote: vote.ToProto(),
+	}
+
+	resp, err := blockExec.proxyApp.VerifyVoteExtensionSync(req)
+	if err != nil {
+		return err
+	}
+
+	if resp.IsErr() {
+		return types.ErrVoteInvalidExtension
+	}
+
+	return nil
+}
+
 // Commit locks the mempool, runs the ABCI Commit message, and updates the
 // mempool.
 // It returns the result of calling abci.Commit (the AppHash) and the height to retain (if any).

state/execution_test.go

@@ -179,14 +179,14 @@ func TestFinalizeBlockValidators(t *testing.T) {
 			[]byte("Signature1"),
 			state.Validators.Validators[0].Address,
 			now,
-      types.VoteExtensionToSign{},
-    )
+			types.VoteExtensionToSign{},
+		)
 		commitSig1 = types.NewCommitSigForBlock(
 			[]byte("Signature2"),
 			state.Validators.Validators[1].Address,
 			now,
-      types.VoteExtensionToSign{},
-    )
+			types.VoteExtensionToSign{},
+		)
 		absentSig = types.NewCommitSigAbsent()
 	)
 

types/block.go

@@ -720,6 +720,7 @@ func (cs *CommitSig) ToProto() *tmproto.CommitSig {
 		ValidatorAddress: cs.ValidatorAddress,
 		Timestamp:        cs.Timestamp,
 		Signature:        cs.Signature,
+		VoteExtension:    cs.VoteExtension.ToProto(),
 	}
 }
 
@@ -731,6 +732,7 @@ func (cs *CommitSig) FromProto(csp tmproto.CommitSig) error {
 	cs.ValidatorAddress = csp.ValidatorAddress
 	cs.Timestamp = csp.Timestamp
 	cs.Signature = csp.Signature
+	cs.VoteExtension = VoteExtensionToSignFromProto(csp.VoteExtension)
 
 	return cs.ValidateBasic()
 }

types/vote.go

@@ -52,12 +52,34 @@ type VoteExtensionToSign struct {
 	AppDataToSign []byte `json:"app_data_to_sign"`
 }
 
+func (ext VoteExtensionToSign) ToProto() *tmproto.VoteExtensionToSign {
+	if ext.IsEmpty() {
+		return nil
+	}
+	return &tmproto.VoteExtensionToSign{
+		AppDataToSign: ext.AppDataToSign,
+	}
+}
+
+func VoteExtensionToSignFromProto(pext *tmproto.VoteExtensionToSign) VoteExtensionToSign {
+	if pext == nil {
+		return VoteExtensionToSign{}
+	}
+	return VoteExtensionToSign{
+		AppDataToSign: pext.AppDataToSign,
+	}
+}
+
+func (ext VoteExtensionToSign) IsEmpty() bool {
+	return len(ext.AppDataToSign) == 0
+}
+
 // BytesPacked returns a bytes-packed representation for
 // debugging and human identification. This function should
 // not be used for any logical operations.
 func (ext VoteExtensionToSign) BytesPacked() []byte {
-	res := make([]byte, len(ext.AppDataToSign))
-	copy(res, ext.AppDataToSign)
+	res := []byte{}
+	res = append(res, ext.AppDataToSign...)
 	return res
 }
 
@@ -86,9 +108,9 @@ func (ext VoteExtension) ToSign() VoteExtensionToSign {
 // debugging and human identification. This function should
 // not be used for any logical operations.
 func (ext VoteExtension) BytesPacked() []byte {
-	res := make([]byte, len(ext.AppDataToSign)+len(ext.AppDataSelfAuthenticating))
-	copy(res[:len(ext.AppDataToSign)], ext.AppDataToSign)
-	copy(res[len(ext.AppDataToSign):], ext.AppDataSelfAuthenticating)
+	res := []byte{}
+	res = append(res, ext.AppDataToSign...)
+	res = append(res, ext.AppDataSelfAuthenticating...)
 	return res
 }
 
@@ -257,11 +279,9 @@ func (vote *Vote) ValidateBasic() error {
 
 func (ext VoteExtension) Copy() VoteExtension {
 	res := VoteExtension{
-		AppDataToSign:             make([]byte, len(ext.AppDataToSign)),
-		AppDataSelfAuthenticating: make([]byte, len(ext.AppDataSelfAuthenticating)),
+		AppDataToSign:             ext.AppDataToSign,
+		AppDataSelfAuthenticating: ext.AppDataSelfAuthenticating,
 	}
-	copy(res.AppDataToSign, ext.AppDataToSign)
-	copy(res.AppDataSelfAuthenticating, ext.AppDataSelfAuthenticating)
 	return res
 }